Field of the Invention
The invention relates to an apparatus for the connection of line sections of a line, through which a hot and highly compressed medium flows, in particular a pipeline, through which steam flows.
A steam feed line for a steam turbine is conventionally constructed for a steam temperature of more than 500.degree. C. and for a steam pressure of more than 300 bar. In a steam feed line of this type, the connection point between a steam-feeding pipeline and a steam inlet valve is conventionally of the welded type. In order to break this connection, for example for assembly or inspection purposes on the steam turbine, the line has to be separated mechanically. In the case of a steam turbine with a steam inlet disposed above a housing parting plane, this signifies a considerable additional outlay in inspection of the steam turbine. During assembly, in addition to the time spent in welding and annealing the connection point, there is the problem of a line which is shortened due to the separating cut, so that undesirable mechanical stresses may be introduced into the line when the connection is made again.
Due to a very high transfer of heat through the hot medium into the flange as a consequence of operation, the use of a conventional flanged connection at this point leads to inadmissible thermal stress within the flange and, in particular, in the region of the flange screws. Since the flange screws are subjected to extreme thermal loading, they may relax to a high degree. The relaxation of the flange screws leads, in turn, to an undesirable loss of force exerted on the parting plane, so that the latter often can no longer be kept closed against the high pressure of the medium flowing through the line.